From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:55088 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964849AbeFRIU2 (ORCPT ); Mon, 18 Jun 2018 04:20:28 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Baolin Wang , Wolfram Sang , Sasha Levin Subject: [PATCH 4.16 116/279] i2c: sprd: Fix the i2c count issue Date: Mon, 18 Jun 2018 10:11:41 +0200 Message-Id: <20180618080613.615384453@linuxfoundation.org> In-Reply-To: <20180618080608.851973560@linuxfoundation.org> References: <20180618080608.851973560@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Baolin Wang [ Upstream commit 2a010461207cc96bee5ab81748325dec1972976f ] We found the I2C controller count register is unreliable sometimes, that will cause I2C to lose data. Thus we can read the data count from 'i2c_dev->count' instead of the I2C controller count register. Signed-off-by: Baolin Wang Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-sprd.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/drivers/i2c/busses/i2c-sprd.c +++ b/drivers/i2c/busses/i2c-sprd.c @@ -368,13 +368,12 @@ static irqreturn_t sprd_i2c_isr_thread(i struct sprd_i2c *i2c_dev = dev_id; struct i2c_msg *msg = i2c_dev->msg; bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK); - u32 i2c_count = readl(i2c_dev->base + I2C_COUNT); u32 i2c_tran; if (msg->flags & I2C_M_RD) i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD; else - i2c_tran = i2c_count; + i2c_tran = i2c_dev->count; /* * If we got one ACK from slave when writing data, and we did not @@ -412,14 +411,13 @@ static irqreturn_t sprd_i2c_isr(int irq, { struct sprd_i2c *i2c_dev = dev_id; struct i2c_msg *msg = i2c_dev->msg; - u32 i2c_count = readl(i2c_dev->base + I2C_COUNT); bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK); u32 i2c_tran; if (msg->flags & I2C_M_RD) i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD; else - i2c_tran = i2c_count; + i2c_tran = i2c_dev->count; /* * If we did not get one ACK from slave when writing data, then we